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Biomedical subjects

D Oliva

Publications and source records attributed to D Oliva.

At least 55 records · Page 3Linked to original sources
PubMed1995

Conserved alternative splicing in the 5'-untranslated region of the muscle-specific enolase gene. Primary structure of mRNAs, expression and influence of secondary structure on the translation efficiency.

We report here the isolation and characterization of cDNAs covering the 5'-end region of mouse and rat mRNAs that encode the beta or muscle-specific isoform of the glycolytic enzyme enolase. As previously determined for humans, two classes of beta-enolase transcripts with distinct sequences in their 5'-untranslated regions are present in both mouse and rat muscles. A mechanism of alternative splicing, conserved from mouse to man, generates the two forms of mRNA. Secondary-structure predictions indicated that, in all cases, a more stable secondary structure could exist in the 5' end of the message with the longer leader. In vitro transcripts containing defined human or mouse 5'-untranslated sequences were obtained by fusion of the different cDNA clones and tested for their relative translational efficiencies in rabbit reticulocyte lysates. Transcripts containing the human long and short leader sequences showed differences in the translational rate, suggesting a role for the 5'-untranslated region in the regulation of translation. No detectable difference was found between transcripts with the two distinct mouse leader sequences. In addition, both transcripts are bound to polysomes and are equally distributed along differently sized polysomes in C2C12 myogenic cells. The relative expression of the two spliced forms in developing and adult muscle tissues by means of reverse transcription and polymerase chain reaction did not show a stage-specific or a tissue-type-specific pattern. A putative functional role for the 5'-untranslated sequences of beta-enolase transcripts is discussed.

Alternative Splicing↗
PubMed1995

Comparison of two orientation systems for indoor travel of blind persons with mental retardation.

Two blind women affected by severe mental retardation were exposed to two previously developed orientation systems. One of the systems was based on acoustic cues, the other on vibratory feedback. The aim was to assess the relative effectiveness of the two systems. Data indicated that the acoustic system ensured a higher frequency of correct moves for one of the subjects and a more rapid performance of the moves for both subjects. The findings are reviewed in relation to the characteristics and applicability of the systems.

Adult↗
PubMed1995

An acoustic orientation system to promote independent indoor travel in blind persons with severe mental retardation.

An acoustic orientation system was devised to promote independent indoor travel in blind persons with mental retardation. The system was assessed with four blind adolescents, all affected by severe mental retardation. Data showed that the system was very useful in helping those adolescents orient and move independently in their daily environment and in a new (generalization) setting. The findings are discussed in relation to the characteristics of the system.

Activities of Daily Living↗
PubMed1994

Promoting ambulation and object manipulation in persons with multiple handicaps through the use of a robot.

A robot was used with a man and a woman affected by blindness, motor disabilities, and mental retardation. The robot was to assist these subjects during their ambulation and allow them to reach a couch (on which to sit) and to transport objects. The data showed that both subjects learned to use the robot, succeeded in transporting and putting away objects, and achieved independent ambulation times of over 22 and 20 min. per session. Staff personnel found the situation in which the subjects were busy with the robot preferable to situations in which the robot was not available.

Activities of Daily Living↗
PubMed1994

The dangerousness of persons with the Othello syndrome.

The Othello syndrome, or delusional jealousy, often raises significant forensic issues, particularly dangerousness. Dangerous patients suffering from the Othello delusion may present with hostility ranging from verbal threats to homicidal acts. We present three cases of individuals suffering from Othello syndrome associated with significant hostility and organic mental factors. We analyze these cases along with Othello syndrome cases culled from the recent anglophonic literature, especially in terms of implications for domestic and public safety.

Adult↗
PubMed1994

A cognitive model of dangerous delusional misidentification syndromes.

The hallmark of the delusional misidentification syndromes is the presence of a misidentification delusion of the self or others. Delusional misidentification may present with an increased risk for dangerous behaviors. Individuals suffering from delusional misidentification syndromes may express hostility in ways ranging from serious verbal threats to homicidal acts. The causes of dangerous misidentification delusions remain for the most part undetermined. In this article, we report a series of six cases of individuals who harbored dangerous misidentification delusions. These individuals were studied phenomenologically and forensically. They were also studied biologically, including neuropsychological testing. A cognitive hypothesis aimed at explaining dangerousness and delusional misidentification is proposed. Implications of the hypothesis for further research are briefly outlined.

Adult↗
PubMed1994

Correlation between leukotriene D4-induced contraction and cytosolic calcium elevation: a quantitative and simultaneous evaluation in smooth muscle.

The role of Ca++ as an intracellular messenger in leukotriene (LT)D4-induced muscle contraction was investigated by measuring force development and elevation in cytosolic Ca++ concentration simultaneously in strips of guinea pig ileal longitudinal muscle loaded with the fluorescent calcium indicator Fura 2. Upon addition of LTD4, a simultaneous increase in tension and cytosolic calcium concentration, [Ca++]i, was observed. Cumulative applications of LTD4 induced concentration-dependent increases in both muscle tension and [Ca++]i, being the half-maximal effect reached at approximately 6 to 9 nM. A statistically significant positive correlation (r = 0.993, P < .001) exists between the two parameters examined. Removal of calcium in the bathing solution, accompanied by addition of 7.5 mM EGTA, completely prevented any increase in either calcium levels or force development, thus indicating a role for Ca++ influx, rather than a release from intracellular stores. All of the LTD4 antagonists tested were able to counteract the effect of the leukotriene on both [Ca++]i and tension increase. However, although LY171883 shifted both of the LTD4 curves to the right in a parallel fashion, FPL 55712 and ICI 198,615 behaved as non-competitive antagonists in reversing the effect of LTD4 on [Ca++]i and tension. Thus, these results strongly suggest that changes in muscle tension induced by LTD4 are attributable to changes in cytosolic free Ca++ concentrations in guinea pig ileum.

Animals↗
PubMed1993

Structural features of the human gene for muscle-specific enolase. Differential splicing in the 5'-untranslated sequence generates two forms of mRNA.

We report here the isolation and characterization of the human gene for the beta or muscle-specific isoform of the glycolytic enzyme enolase. The nucleotide sequence analysis revealed structural features, such as organization as 11 coding exons, the first exon consisting of an untranslated sequence and hence resembling sequences of the other two members of the gene family, the alpha and gamma enolase genes. The beta enolase locus spans about 6 kbp genomic DNA. Sequences matching the consensus sequence for muscle-specific regulatory factors are present in the 5'-flanking region and within the first intron. A combination of primer extension, S1 nuclease protection and RNA-sequencing experiments indicates that the gene has a unique transcriptional start site, 26 bp downstream of a TATA-like box; the differential usage of two donor sites within the untranslated exon I generates two alternatively spliced transcripts. The existence of the two mRNA, differing from one another in the presence or absence of a 42-nucleotide fragment in the leader sequence, was confirmed by cloning the corresponding cDNA using the rapid amplification of cDNA ends strategy. Secondary-structure predictions indicated that the leader sequences of the spliced forms could form hairpin structures with different free energies of formation, suggesting translational control.

Base Sequence↗
PubMed1993

Clinical and magnetic resonance features of the classic and akinetic-rigid variants of Huntington's disease.

We studied 32 patients with confirmed Huntington's disease (HD); six (mean age, 31.7 years) had the akinetic-rigid form and 26 (mean age, 46.1 years) had the classic hyperkinetic form. Clinical examination included a count of abnormal involuntary movements, motor self-sufficiency evaluation by the Physical Disability Rating Scale, cognitive function assessment by the Mini-Mental State examination, and a verbal fluency test. Magnetic resonance imaging permitted measurement of bicaudate diameter, a sensitive indicator of caudate atrophy in HD. Patients with the akinetic-rigid form of HD were younger and had earlier disease onset than those with the classic form of HD. All patients with akinetic-rigid HD (group 1) had striatal hyperintensity on T2-weighted magnetic resonance images; seven patients with classic HD (group 2) had a similar abnormality. Groups 1 and 2 were in fact similar in all other respects, except that the number of abnormal involuntary movements was greater in group 2. Groups 1 and 2 together had significantly younger age at onset, lower Mini-Mental State Examination score, more severe motor disability, worse verbal fluency test result, and greater bicaudate diameter than the 19 patients with classic HD without magnetic resonance signal abnormality (group 3) and appear to be a uniform population, distinct from group 3. The abnormalities on magnetic resonance images indicated greater striatal damage in groups 1 and 2, which could be the neuroanatomic substrate of their greater motor and cognitive compromise.

Adult↗
PubMed1993

Adult onset myoclonic Huntington's disease.

A patient with adult onset Huntington's disease (HD) and prominent action myoclonus is described. Neither epileptiform activity nor electroencephalography (EEG) correlates of the movements was found. Unlike the case with most (nonmyoclonic) HD patients, centro-parietal components of somatosensory evoked potentials (SEPs) were well defined and a clear V2 response was found. Treatment with valproic acid greatly reduced myoclonus suggesting that the gamma-aminobutyric acid (GABA) system might be involved in the pathophysiology of myoclonus in HD.

Adult↗
PubMed1993

Differential expression of neuron-specific enolase mRNA in mouse neuroblastoma cells in response to differentiation inducing agents.

1. The mouse neuroblastoma cell line N-115 was used as a model system to study neuronal differentiation induced by treatment of cells with different agents. 2. The extent of morphological differentiation obtained with dibutyryl cyclic AMP (dbc-AMP), dimethyl sulfoxide (DMSO), retinoic acid (RA), and serum-free medium was correlated to the expression of the mRNA for the gamma isoform of the glycolytic enzyme enolase, a recognized neuron-specific marker. 3. A 4-day treatment of the cells with any of the differentiation inducing agents used in this study resulted in the extension of long neurites, though differences in cell body shape were observed depending on the agent used. 4. Northern blot analysis revealed that changes in the level of gamma enolase-specific mRNA correlate with the extent of morphological differentiation, with a 5- to 20-fold increase depending on the differentiation inducing agent used. 5. Finally, we found that a high cell density causes a significative increase in the level of the gamma enolase-specific message in cells maintained in growing conditions.

Animals↗
PubMed1993

Building choice opportunities within occupational programmes for persons with profound developmental disabilities.

Choice opportunities were arranged within the occupational programmes of two subjects with profound developmental disabilities. The subject participating in Experiment 1 was already familiar with a computer-aided programme aimed at promoting independent occupation. That programme was now extended to allow him to choose activities and reinforcers. He was also exposed to a control programme involving the use of folders with drawings. The subject participating in Experiment 2 had no previous experience with special programmes. For this subject, two versions of a computer-aided programme were used: one to teach occupational engagement without choice; and the other occupational engagement with choice. The results have shown that the first subject was very successful in combining choice behaviour and constructive activity with the computer-aided programme, but not with the control programme. The second subject learned very rapidly independent activity engagement, but required relatively long time to develop 'meaningful' choice behaviour. General implications of the findings are discussed.

Adult↗
PubMed1992

Non-serotonergic 3H-ketanserin binding sites in human platelets: characteristics and interaction with calcium antagonists.

Here we report the identification of binding sites for 3H-ketanserin in human platelet membranes. At 4 degrees C, 3H-ketanserin binding is saturable (Bmax = 0.58 pmol/mg protein), rapid (equilibrium being attained within 20 min) and reversible. The kinetics of the association and dissociation curves are consistent with the existence of a single class of binding sites, as confirmed also by computer-assisted analysis of the saturation curve. Specific binding is increased by Ca2+ and Mg2+. 3H-ketanserin binding is inhibited by serotonin (Ki = 48.5 microM), unlabeled ketanserin (Ki = 3-15 nM), as well as by another antiserotonergic drug, methysergide (Ki = 32.6 microM). However, other selective 5-HT2 ligands, such as ritanserin, spiperone and cyproheptadine fail to interact with 3H-ketanserin binding. On the contrary, tetrabenzine, a monoamine depleting agent, when preincubated at 30 degrees C, did inhibit the specific binding completely. 3H-ketanserin specific binding is inhibited in a dose-dependent fashion by some calcium blocking agents, with different potencies: verapamil (Ki = 2.25 microM), diltiazem (Ki = 139 microM) and SIM6080, a new Ca(2+)-antagonist related to the phenylalkylamines (Ki = 5.22 microM). Flunarizine inhibited 3H-ketanserin specific binding only at relatively high concentrations (IC50 greater than 100 microM), while nitrendipine did not show any inhibitory effect up to 20 microM. The present evidence indicates that all the sites labeled by 3H-ketanserin at 4 degrees C might be coincident with the monoamino transporter identified in other systems, and that they might play a role in the modulation of platelet aggregation exerted by some calcium blocking agents.

Binding Sites↗
PubMed1991

Eicosanoid release and mepyramine, LTC4 and LTD4 binding in passively sensitized human lung parenchyma in vitro.

In vitro passive sensitization of human lung parenchyma with hyper-immune serum did not affect the release of prostaglandin D2 (PGD2) or leukotriene (LT)-like activity upon challenge with anti-IgE antibody with respect to control lung, despite a marked difference in IgE levels between control (C) and sensitized (S) tissue. Binding studies with [3H]LTC4, [3H]LTD4 and [3H]mepyramine (a histamine H1 antagonist) showed a statistically significant increase in the amount bound in sensitized vs control lung for [3H]mepyramine only. Contractile response to 5 x 10(-5) M histamine (H) in C and S lung parenchymal strips did not correlate with binding data. It is concluded that in vitro elevated IgE levels do not affect the interaction of sulfidopeptide leukotrienes with their putative receptors. As for the observed increase in [3H]mepyramine binding, this might not represent a true increase in histamine receptors on lung smooth muscle cells.

Animals↗
PubMed1991

Complete structure of the human gene encoding neuron-specific enolase.

At least three genes encode the different isoforms of the glycolytic enzyme enolase. We have isolated the gene for the human gamma- or neuron-specific enolase and determined the nucleotide sequence from upstream to the 5' end to beyond the polyadenylation site. The gene contains 12 exons distributed over 9213 nucleotides. Introns occur at positions identical to those reported for the homologous rat gene, as well as for the human alpha- or nonneuronal enolase gene, supporting the existence of a single ancestor for the members of this gene family. Primer extension analysis indicates that the gene has multiple start sites. The putative promoter region lacks canonical TATA and CAAT boxes, is very G + C-rich, and contains several potential regulatory sequences. Furthermore, an inverted Alu sequence is present approximately 572 nucleotides upstream of the major start site. A comparison of the 5'-flanking region of the human gamma-enolase gene with the same region of the rat gene revealed a high degree of sequence conservation.

Amino Acid Sequence↗